import java.util.Scanner;

/*
    @author:sa
    @date:2024/11/6 17:02
*/
public class Test03 {
    public static void main(String[] args) {
        System.out.println("请输入华氏温度");
        Scanner scanner= new Scanner(System.in);
        double str1=scanner.nextDouble();
        double s1=(str1-100)*5/9;
        System.out.println(s1);
    }
}
